Hi,
Today we had about +8 deg C and I went out flying my Mavic 2 Pro. I always check the IMU and compas calibration before flying. I started the drone and the remote controller and checked that the IMU and compass values were good, which they were. I still hade the display for the IMU up on my phone and then started the propps and to my surprice I saw that the IMU values disapeared. I thought that this may not be right, so I shut everything down and started it all upp again from the beginning and saw the same thing happening. This time I looked at the values from the IMU and they all went away again when I started the propps, I was not yet flying. Now I saw that under these values that normally are displayed, it said MOVING. Perhaps this is normal and the IMU values can not be displayied when the propps has started and you are about to fly. I have not read about this anywhere and would just like to have a confirmation that this is correct and normal. Thank you.

I cannot confirm this (as of yet, but will look at this on my Mav Pro Gen I in the next couple of days),
but it sounds right.
When you power up the AC, and when it has finished booting, and you hear the nice lady say "the homepoint has been recorded, please check it on the map"
That is when you should check your compasses and IMU states in the Go4 App. All should be in the green.
Sometimes folks get in a hurry and sometimes move the AC while booting. A solid NO NO. This can mess with the IMU (which has to be correct when it uses the compasses.
But when you check the sensor states, all should be in the green and you should be good to go.

Thank you for your reply.
I always let the AC stand on the ground first and do all checks, so it has certainly booted before I take off. Both compass and IMU are green in the beginning and its only when I start the props after about 3-4 minutes that the IMU disappears and it says MOVING under where the values should be. I will do a check today and follow your advice and come back here.

I always check the IMU and compas calibration before flying.
That's unnecessary.
Unless you modify the drone or place it on something steel, the compass should be fine and the IMU will be fine unless the drone has crashed hard.
And if you put teh drone down close to something made of steel, recalibrating isn't the answer - powering down and moving the drone away is.

Labroides Posted at 3-17 00:12
I always check the IMU and compas calibration before flying.
That's unnecessary.
Unless you modify the drone or place it on something steel, the compass should be fine and the IMU will be fine unless the drone has crashed hard.

OK thanks mate.
At the moment I always take off and land from the same spot every time, so nothing should change. I just came a cross this thing that the IMU readings disappeared when I started the props, when I decided to check the IMU and compass.

Flycaster Posted at 3-16 11:21
I cannot confirm this (as of yet, but will look at this on my Mav Pro Gen I in the next couple of days),
but it sounds right.
When you power up the AC, and when it has finished booting, and you hear the nice lady say "the homepoint has been recorded, please check it on the map"

Hi again,
Just back from a test flight today.
I can see the IMU being green and OK when the drone is started and connected to the remote controller. However, as soon as I start the motors is says MOVING and no green bar any more, just nothing. I take off and hear the voice that the home point is recorded and than look at the IMU again and it says MOVING. The same thing any time while flying. This to me looks like as soon as you start the props or get home point set or flying, you can not see the IMU values any more  and there is the text MOVING. I do not know if this is right but think so. Perhaps some one can confirm this. Thanks.
Edit: Just noticed that while flying there is a small blue dott next to the Accelerometer ACC0 end at the bottom of that page it says In Use. there is also a number for that which displays 0.019. There is nothing displayed for the ACC1, more than Moving and the number 0.000.

For the gyrocope GY00 is says 0.007 and for GYR01 it says 0.007 and MOVING for both gyros.

There is no green bar for anny of the IMU levels.

Perhaps these values are represented with these numbers instead of the green bars?

Edit. I can now confirm that the accelerometer values for ACCO and ACC1 as well as Gyroscope values for GYR00 and GYR01 as above are the same green bars I see before starting the props as when I am flying.

This picture is when AC is on the ground and turned on, but props not on.

This is IMU when AC is on the ground and props not started.



This is when AC has taken off and home point is confirmed.